1. Field of the Invention
The present invention relates to a bump stopper for a suspension system. More particularly, the present invention relates to a bump stopper for a suspension system that contacts a stopper plate in a case of excessive turning so as to prevent chassis components from being overlapped with each other.
2. Description of Related Art
Generally, a suspension system of a vehicle is disposed between a vehicle body and a vehicle wheel, and connects the vehicle body with the vehicle wheel by using a plurality of links. A suspension system of coupled torsion beam axle (CTBA) type is one of such suspension systems of a vehicle.
As shown in FIG. 1, the suspension system of a CTBA type includes a torsion beam 1 disposed to a horizontal direction, and trailing arms 9 are welded to both ends of the torsion beam 1. A spindle bracket 7 for installing a tire 3 and a wheel 5 to the trailing arm 9 is provided at one end thereof.
In addition, a bushing 11 for connecting the trailing arm 9 to a vehicle body (not shown) is provided at the other end of the trailing arm 9, and a spring seat 15 for mounting a spring 13 and a mounting pin 19 for connecting a shock absorber 17 to the trailing arm 9 are mounted respectively at the one end and a middle portion thereof.
According to such a suspension system, a stopper plate 21 is mounted at an upper surface of the spring seat 15, and an upper end of the spring 13 is connected to the vehicle body. An upper portion of the spring 13 encloses a bump stopper 23 confronting the stopper plate 21.
The bump stopper 23 limits a maximum bump stroke and is provided respectively at both ends of the vehicle body. Here, “bump” means that the vehicle body goes toward the ground in a case that a vehicle turns, and “rebound” means the vehicle body goes up in an opposite direction of the ground.
In a case of excess turning, the bump stopper 23 contacts the stopper plate 21 and applies a load thereto so as to prevent chassis components from being overlapped with each other.
Such a bump stopper 23, as shown in FIG. 2, includes at least two convex portions B1 and B2 contacting each other in a compressed state, it limits the bump stroke of the suspension system, and it insulates low and high frequency vibration and impact. The bump stopper 23 is generally made of polyurethane materials. However, polyurethane materials is more expensive than rubber materials, and thus the material cost of the bump stopper 23 made of polyurethane materials is high.
On the contrary, when the bump stopper 23 is made of rubber materials, vibration-absorption capacity may be deteriorated since the damping coefficient of rubber materials is nearly “0”. Therefore, additional energy-absorbing devices for lowering a peak value of vibration and impact applied to the bump stopper 23 may be required.
In addition, if a bump stopper 23 made of rubber materials has the same shape as a bump stopper 23 made of polyurethane materials, durability at overlapped portions P1, P2, and P3 of rubber materials as well as insulation capacity may be deteriorated, as shown in FIG. 3. Insulation capacity can be secured by reducing the thickness of the bumper stopper 23 or by boring holes that affect the damping capacity of materials, but durability of the bump stopper having the general shape cannot be secured because of a parting line PL created in a bonding process of the rubber materials.
The information disclosed in this Background of the Invention section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.